The space age began with the launch of Sputnik I in 1957 by the Soviet Union. Since then numerous spacecraft and astronomers have explored space.  The Sputnik II in 1957 carried the first creature into space. It was a dog named Laika. In 1961, Yuri Gagarin from the Soviet Union became the first human to travel into space. Gagarin achieved this feat abroad the spacecraft Vostok 1, on 12 April 1961.


After the Soviet Union, the United States worked towards advances in space travel. in 1961, the first American manned spacecraft was carried by Alan Shepard. After the launch of the first spacecraft, President John F. Kennedy announced the goal of landing an American astronaut on the moon by the end of the 1960s. In 1962, the National Aeronautics and Space Administration launched a spacecraft named Friendship. It was piloted by John Glenn and it orbited the Earth three times. Later, in 1969, Neil Armstrong became the first human being to step on the moon.







Astronauts:

An astronaut or cosmonaut is a person who commands, pilots, or serves as a crew member of a spacecraft. Astronauts are trained for space travel in spaceflight programs, Until 2003, professional astronauts were trained exclusively by governments, |However, some astronauts are also trained by private bodies. They are called commercial astronauts. During the training program, the astronauts learn to control the flight simulator in the shuttle. They are trained about weightlessness or zero gravity. They are also trained underwater to get used to weightlessness. They learn how to get out of the space shuttle during an emergency landing or take off.







Micro-gravity(Zero Gravity):

Gravity is a force that governs motion throughout the universe. An object falls on Earth due to Earth's gravity. Many people mistakenly think that there is no gravity in space. In fact, space has extremely low gravity. It is about 0.000001 percent of Earth's Gravity. Therefore, it is said that space has zero gravity or more accurately micro-gravity. Due to micro-gravity, objects are in a state of free-fall and are said to be weightless.







Effects of micro-gravity:

Micro-gravity affects both equipment and people. Many astronauts fall sick as they experience micro-gravity. Their muscles grow weak and the heart and blood vessels became lazy after a few weeks. Astronauts can also suffer from demineralization, weakening of bones, after a long stay in space. They often try to overcome the effects of micro-gravity by spending time cycling and on the treadmill for at least 30 minutes every day. The interior of the spacecraft has lockers and hooks. Astronomers keep everything strapped and stowed in lockers or strap them to the walls with velcro so that they do not float away.






Working in Space :

Astronauts perform many tasks in the space shuttle and space station. The space shuttle provides facilities to perform science experiments, and release and capture huge satellites. The space station is designed to perform world-class science and research work that only the microgravity environment can provide. The station crews perform and monitor science experiments. They check the support system as well as repair and maintain equipment. They even exchange messages with medical experiments to study the effects of micro-gravity on different materials and living beings.








Extravehicular activity(EVA):

Astronomers often step out of their vehicle into space to work. This is known as EVA. During this period, astronauts put on their spacesuits and move to a special two-doored chamber known as airlock. They then leave the spacecraft from the airlock. Astronauts can work in space for six-eight hours.









Space Probes:

Space Probes are space missions that explore different celestial bodies in space or conduct experiments. They make observations of temperature, radiation, and objects and send them back to Earth for scientists to study them. Space probes are robotic missions and do not have people on them. Most space probes return to Earth. Some are designed to land on other planets and collect information about the conditions on the planet. Sputnik I was the first space probe that was launched in 1957.